Semiconductor device having insulating layer including polyimide film

Abstract

A semiconductor device has a passivation layer including a polyimide film. Argon ions are implanted in the polyimide film to convert it into an electrically stable insulating film.

What is claimed is: 
     
       1. A semiconductor device, comprising: a semiconductor substrate;   at least one semiconductor element formed in one main surface region of the substrate by means of impurity diffusion;   an insulating film formed on the main surface of the substrate;   a first wiring layer selectively formed on the insulating film and connected to the semiconductor element formed in the substrate by at least one through-hole made in the insulating film;   a polymide film formed as an insulating layer to cover both the first wiring layer and the exposed surface of the insulating film, said polymide film being provided with at least one through-hole positioned over a part of the first wiring layer, and said polyimide film having implanted therein a controlled dose of ions of an inert element for suppression of polarization; and   a second wiring layer selectively formed on said polyimide film having ions of the inert element implanted therein and connected via the through-hole made in said polyimide film to said part of the first wiring layer, said semiconductor device being designed to have a potential difference applied between the substrate and said second wiring layer.   
     
     
       2. A semiconductor device according to claim 1, wherein the inert element is argon. 
     
     
       3. A semiconductor device according to claim 2, wherein the dose of the Ar ions ranges between 3×10 13  cm -2  and 2×10 15  cm -2  ; and the damage to the polymide film, i.e., the value of "implanting power (W/cm 2 )×dose (Qd/cm 2 )", ranges between 4.5×10 12  (W/cm 4 ) and 3.5×10 14  (W/cm 4 ). 
     
     
       4. A semiconductor device according to claim 1, wherein the insulating film is formed of silicon dioxide. 
     
     
       5. A semiconductor device according to claim 1, wherein the insulating film is formed of silicon nitride. 
     
     
       6. A semiconductor device, comprising: a semiconductor substrate;   at least one semiconductor element formed in one main surface region of the substrate;   an insulating film formed on the main surface of the substrate;   a first wiring layer selectively formed on the insulating film and connected to the semiconductor element formed in the substrate by at least one through-hole made in the insulating film;   a polyimide film formed as an insulating layer to cover both the first wiring layer and the exposed surface of the insulating film, said polyimide film being provided with at least one through-hole positioned over a part of the first wiring layer;   a second wiring layer selectively formed on said polyimide film and connected via the through-hole made in said polyimide film to said part of the first wiring layer, said semiconductor device being designed to have a potential difference applied between the substrate and said second wiring layer; and   means in said polyimide film for suppressing polarization of said polyimide film when a potential differing from that applied to the substrate is applied to the second wiring layer, said polarization suppressing means consisting of a dose of inert element ions implanted into said polyimide film.   
     
     
       7. A semiconductor decide according to claim 6, wherein said inert element ions are argon ions. 
     
     
       8. A semiconductor device according to claim 7, wherein the dose of the Ar ions ranges between 3×10 13  cm -2  and 2×10 15  cm -2  ; and the damage to the polyimide film, i.e., the value of "implanting power (W/cm 2 )×dose (Qd/cm 2 )", ranges between 4.5×10 12  (W/cm 4 ) and 3.5×10 14  (W/cm 4 ).